Tom,

If you are drilling a hole for the sump return, it sounds like you are sending the return in thru the bottom of the tank. How do you stop the sump from overflowing when you turn things off? Is there a ball valve just under the return bulk head? I would imagine that ball valves can leak, if not cleaned occasionally. So, do you have a valve above the ball valve too, so you can remove and clean the ball valve occasionally? I'm thinking long-term maintenance and also not flooding my room with 100+G of water.